[PATCH v2] mmc: bcm2835: Use dma_request_chan() instead dma_request_slave_channel()

Nicolas Saenz Julienne nsaenzjulienne at suse.de
Tue Jan 7 02:49:43 PST 2020


On Tue, 2020-01-07 at 12:40 +0200, Peter Ujfalusi wrote:
> dma_request_slave_channel() is a wrapper on top of dma_request_chan()
> eating up the error code.
> 
> By using dma_request_chan() directly the driver can support deferred
> probing against DMA.
> 
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi at ti.com>
> ---
> Hi,
> 
> Changes since v1:
> - jump to err: instead of returning in case of EPROBE_DEFER
> 
> Regards,
> Peter

Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne at suse.de>

Thanks,
Nicolas

> 
>  drivers/mmc/host/bcm2835.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
> index 99f61fd2a658..c3d949847cbd 100644
> --- a/drivers/mmc/host/bcm2835.c
> +++ b/drivers/mmc/host/bcm2835.c
> @@ -1393,7 +1393,17 @@ static int bcm2835_probe(struct platform_device *pdev)
>  	host->dma_chan = NULL;
>  	host->dma_desc = NULL;
>  
> -	host->dma_chan_rxtx = dma_request_slave_channel(dev, "rx-tx");
> +	host->dma_chan_rxtx = dma_request_chan(dev, "rx-tx");
> +	if (IS_ERR(host->dma_chan_rxtx)) {
> +		ret = PTR_ERR(host->dma_chan_rxtx);
> +		host->dma_chan_rxtx = NULL;
> +
> +		if (ret == -EPROBE_DEFER)
> +			goto err;
> +
> +		/* Ignore errors to fall back to PIO mode */
> +	}
> +
>  
>  	clk = devm_clk_get(dev, NULL);
>  	if (IS_ERR(clk)) {

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